The Iowa Utilities Board issued an order to natural gas companies today as part of its emergency investigation into billing practices. The Iowa Utilities Board is ordering natural gas utilities to comply with what’s called the “reasonableness rule.” Board spokesman Rob Hillesland says the rule requires utilities to consider a customer’s income, expenses and ability to pay when entering an agreement for paying overdue bills. Hillesland says the I-U-B wanted to make sure the rule was clearly understood by the utility companies. The I-U-B began it’s investigation after the extremely cold winter and big increases in natural gas prices led to a 90-percent increase in the money owed by natural gas customers behind on their bills. The board earlier extended the mandatory cutoff time by a month for low-income Iowans who’re behind on paying their gas bills. Hillesland says they haven’t closed the book on the investigation just yet. He says they’ll continue to look at the budget billing practices and possibly changing the rules regarding billing.Hillesland says Iowa customers were behind on their natural gas bills by more than 47-million dollars.